Domestic production of motor vehicles in Japan sank to its lowest level in 21 years in fiscal 1999, totaling fewer than 10 million units for the second straight year, the Japan Automobile Manufacturers Association said Wednesday.

The output by Japan’s 11 automakers in the year that ended March 31 came to 9,932,333 units, down 0.4 percent from the year before and the lowest since fiscal 1978, when production totaled 8,946,442 units, the association said.

An association official attributed the contraction to sluggish exports, which more than offset growth in domestic demand led by booming sales of minivehicles with engine capacity of up to 660cc.

The association expects annual output to recover to the 10 million mark in fiscal 2000, the official said, based on predictions that Japan’s economy will improve in the latter half of the fiscal year.

According to separate reports released the same day by five major Japanese automakers, Toyota Motor Corp. ranked top in worldwide motor vehicle production, with 4,881,837 units in fiscal 1999, up 6.4 percent over the previous year.

Honda Motor Co. topped Nissan Motor Co. for the first time in fiscal yearlong global production with 2,440,200 units, up 4.4 percent, while the latter’s output dropped 2.5 percent to 2,404,650 units, according to the makers’ data.

Worldwide production by Mitsubishi Motors Corp. totaled 1,727,962 units, up 2.6 percent, and output by Mazda Motor Corp. came to 956,135 units, up 0.6 percent.